Manager Howard Wilkinson needed permission to replace him with Bjorklund on the teamsheet from both the match referee and Manchester City before kick-off at the Stadium of Light.
"I twisted my ankle in warm up - it was just a freak incident but very unlucky for the club that it happened just before the game," said Craddock.
Scans on the ankle have indicated it is not as bad as it could have been: "Jody has had an initial scan but we will need to re-assess his injury again in 48 hours after swelling has gone down because scans can be unclear when there is lots of swelling due to fluids," said Wilkinson.
"The early signs indicate that the injury may not be as bad as we feared and could take less than the usual 3-4 weeks to heal."